A wall of chewing gum moonlights as collective art.

A walk through the historic city center, under the streets of Seattle.

A giant Troll lurks under one of Seattle's oldest bridges.

One man's attempt to create an artistic wonder on a run-down block in Detroit.

A four story, football field-sized, nine-grotto creation made of shells, minerals, and rare stones.

A striking sculpture built to honor the women of the Lakota and Dakota Nations.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

This town is home to the world’s largest arch constructed entirely of elk antlers.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

The first declared National Monument in the United States.

Along a California highway is a kind of Jurassic Park made of metal.

Most of this “research national monument” still lies buried beneath the earth.

The ghostly remains of an accidental sea.

This conservation area is also home to many of the region's desert tortoises.

An eerie natural formation that looks right back at you.

A 250 million-year-old rock formation has earned a rather unique nickname.

A sign at the end of the Santa Monica Pier marks the traditional end of the legendary American highway.

This maintained cabin is where Josie Morris, an occasional associate of Butch Cassidy, lived out the last 50 years of her life by herself.

Inside this striking glass building, visitors can see thousands of dinosaur fossils in the positions that nature deposited them more than 150 million years ago.

A tunnel with windows, so you don't miss out on the impressive views.

Settled by the Church of Jesus Christ of Latter-day Saints in 1859, this abandoned frontier town has appeared in several films.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.